We just got back last week from Oahu and the Big Island. We did 6 at Waikoloa (Hilton) and 3 nights at the Ko'Olina Beach Club. This was my second trip to the Big Island and even 6 nights wasn't enough. We really enjoyed the Marriott Ko'Olina Beach Club for the first three nights on Oahu. We walked up to the JW for breakfast one morning. You're going to love the lagoons (all 4 of them) at the JW. Walk down to the Ko'Olina and take the timeshare tour for 90 minutes and pick up 15,000 MR points. It's very low pressure.

Have you thought about trying to get a 1 or 2 bedroom villa at the Ko'Olina instead of the JW? It would give you a lot more privacy than a standard room at the JW given that your kids are going along.